1. Field of the Invention
The present invention relates to a pulsed solar simulator, and, in particular, a solar simulator that can be used for measuring solar cells such as single-junction solar cells and multi-junction solar cells.
2. Discussion of Background Information
Solar simulators are used to simulate natural sunlight to make it possible to study the effects of sunlight on certain objects to be irradiated, even under laboratory conditions. A special application is the study of the capacity of solar cells.
Solar simulators are known, e.g., from U.S. Pat. No. 4,641,227, in which simulation of sunlight is realized through a suitable arrangement and filtering of two independent radiation sources and a subsequent overlapping of the radiation emitted from these radiation sources. However, pulsed radiation sources are not used as radiation sources here. Focusing parabolic mirrors are arranged around these radiation sources at a distance such that the radiation sources are located respectively in the focus of the parabolic mirrors in order to focus the radiation in the direction of the target to be irradiated.
German Patent Application No. DE 201 03 645 describes a pulsed solar simulator with displaceable filter, in which the spectrum of a flash lamp is adjusted to the spectrum of the sun by suitable displaceable filters.
European Patent Application No. EP 1 139 016 describes a pulsed solar simulator in which, with the aid of flat mirror elements arranged at a distance from a pulsed radiation source, as a rule in parabolic form, the radiation source is arranged in the focus, which ensures an improved illumination of the target to be irradiated. The spectrum of the beam clusters reflected by the mirror elements can also be suitably adjusted with the aid of filters in order to achieve an additional irradiation of the target in a desired wavelength range.
However, none of these possibilities from the prior art gives an indication of how to achieve an improved homogeneity of the irradiation of the target to be irradiated.